Observed drag crisis on a sphere in flowing He I and He II

The pressure distribution on the surface of a sphere has been measured in f lowing He I and He II as a function of Reynolds number. The drag coefficien t was extracted by integrating the pressure distribution, using some assump tions about symmetry of the flow field. Drag coefficients are plotted again st Reynolds number for both He I and He II against classical data for both smooth and nonsmooth spheres. Latest results in He II suggest that the drag crisis occurs at a Reynolds number of approximately 2 X 10(5), in fair agr eement with classical data. (C) 1999 American Institute of Physics. [S1070- 6631(99)01004-1].